Internal cooling system with corrugated insert forming nearwall cooling channels for airfoil usable in a gas turbine engine

ABSTRACT

An airfoil for a gas turbine engine in which the airfoil includes an internal cooling system formed from one or more midchord cooling channels with a corrugated insert positioned therein and creating nearwall leading edge, pressure side and suction side nearwall cooling channels. The corrugated insert may be formed from a wall that oscillates in a repeating pattern between peaks and valleys, such that the peaks are closer to an inner surface of the outer wall forming the generally elongated hollow airfoil The corrugated insert may work in concert with the rows of partition walls to create periodic impingement on the inner surface of the outer wall Such cooling system provides adequate cooling for use in environments in which few, if any, cooling holes are desired, such as in crude oil engine applications

FIELD OF THE INVENTION

This invention is directed generally to gas turbine engines, and moreparticularly to internal cooling systems for airfoils in gas turbineengines

BACKGROUND

Typically, gas turbine engines include a compressor for compressing air,a combustor for mixing the compressed air with fuel and igniting themixture, and a turbine blade assembly for producing power. Combustorsoften operate at high temperatures that may exceed 2,500 degreesFahrenheit Typical turbine combustor configurations expose turbine vaneand blade assemblies to high temperatures As a result, turbine vanes andblades must be made of materials capable of withstanding such hightemperatures, or must include cooling features to enable the componentto survive in an environment which exceeds the capability of thematerial Turbine engines typically include a plurality of rows ofstationary turbine vanes extending radially inward from a shell andinclude a plurality of rows of rotatable turbine blades attached to arotor assembly for turning the rotor

Typically, the turbine vanes are exposed to high temperature combustorgases that heat the airfoil. The airfoils include internal coolingsystems for reducing the temperature of the airfoils. While there existmany configurations of cooling systems, there exists a need for improvedcooling of gas turbine airfoils.

SUMMARY OF THE INVENTION

An airfoil for a gas turbine engine in which the airfoil includes aninternal cooling system formed from one or more midchord coolingchannels with a corrugated insert positioned therein and creatingnearwall leading edge, pressure side and suction side nearwall coolingchannels is disclosed. The corrugated insert may be formed from a wallthat oscillates in a repeating pattern between peaks and valleys, suchthat the peaks are closer to an inner surface of an outer wall forming agenerally elongated hollow airfoil of the airfoil. The corrugated insertmay work in concert with the rows of partition walls to create periodicimpingement on the inner surface of the outer wall, specifically thesurfaces leading from the valleys to the peaks moving toward a trailingedge of the generally elongated hollow airfoil direct the fluids towardthe outer wall. Such cooling system may provide adequate cooling for usein environments in which few, if any, cooling holes are desired, such asin crude oil engine applications

The turbine airfoil may be formed from a generally elongated hollowairfoil formed from an outer wall, and having a leading edge, a trailingedge, a pressure side, a suction side, and a cooling system positionedwithin interior aspects of the generally elongated hollow airfoil Thecooling system may include one or more midchord cooling channels withone or more corrugated inserts positioned therein and creating a leadingedge nearwall cooling channel between the leading edge and thecorrugated insert, a suction side nearwall cooling channel between thesuction side and the corrugated insert and a pressure side nearwallcooling channel between the pressure side and the corrugated insert. Thecorrugated insert may be formed from a wall that oscillates in arepeating pattern between peaks and valleys, such that the peaks arecloser to an inner surface of the outer wall forming the generallyelongated hollow airfoil. A plurality of rows of partition walls mayextend from the inner surface forming the outer wall and into themidchord cooling channel. The partition walls may include gaps therein,and the rows of partition walls may be generally aligned with adirection of cooling fluid flow from the leading edge chordwise towardthe trailing edge. At least a portion of the peaks in the corrugatedinsert extending radially outward may be aligned with the gaps within atleast a portion of at least one partition wall.

In at least one embodiment, one or more partition walls may include gapstherein that extend for a portion of or in a repeating pattern for anentire length of the at least one partition wall In one embodiment, oneor more partition walls may be linear In another embodiment, each of thepartition walls may be linear and each of the partition walls may beparallel with each other. In yet another embodiment, one or morepartition walls may be formed from first and second subpartition walls,whereby the second subpartition wall may be offset laterally from firstsubpartition wall, and the first and second subpartition walls may bestaggered in an alternating manner moving downstream in a direction fromthe leading edge toward the trailing edge. In another embodiment, eachpartition wall may be formed from a first and second subpartition walls,whereby the second subpartition wall may be offset laterally from firstsubpartition wall, and the first and second subpartition walls may bestaggered in an alternating manner moving in a direction from theleading edge toward the trailing edge. A second subpartition wall may bepositioned along an axis that is equidistant from a first subpartitionwall within a same partition wall as the second subpartition wall andfrom a first subpartition wall within an adjacent partition wall

The turbine airfoil may also include a plurality of miniribs extendingfrom the inner surface forming the outer wall and extending betweenadjacent partition walls. The miniribs may be nonparallel with thepartition walls and may be shorter in height extending from the innersurface than adjacent partition ribs. In at least one embodiment, theplurality of miniribs may be aligned with each other and may beorthogonal to the adjacent partition walls

The cooling system may also include one or more trailing edge coolingchannels positioned between the midchord cooling channel and thetrailing edge of the generally elongated hollow airfoil. The trailingedge cooling channel may include a plurality of pin fins extending fromthe outer wall forming the pressure side to the suction side and formingzigzag cooling flow channels within the trailing edge cooling channel Atleast a portion of the pin fins may have cross-sectional areas with aleading edge and a trailing edge that is positioned on a downstreamcorner and separated from the leading edge by a concave side surface anda convex side surface. At least one of the zigzag cooling flow channelsmay be formed from a plurality of pin fins aligned such that the concaveand convex side surfaces alternate moving towards the trailing edge. Inat least one embodiment, a first upstream pin fin may have across-sectional area formed from an upstream section and a downstreamsection. The upstream section may be generally linear with a constantwidth, and the downstream section may be generally linear with a taperedwidth that reduces in width moving towards the trailing edge. Theupstream and downstream sections may be nonlinear and nonorthogonal witheach other.

During use, cooling fluids are supplied from a compressor or other suchsource to the inner aspect of the corrugated insert of the internalcooling system Cooling fluids are passed through the inlets into theleading edge nearwall cooling channel where the fluids separate with aportion flowing into the pressure side nearwall cooling channel and aportion flowing into the suction side nearwall cooling channel. Thepeaks and valleys of the corrugated insert create periodic impingementon the inner surface of the outer wall The partition walls also directthe cooling fluids towards the trailing edge, and in at least comeembodiments, create a nonlinear flow path toward the trailing edge toincrease convection of heat from the outer wall to the cooling fluid Thecooling fluid may be exhausted through film cooling holes at downstreamends of the pressure and suction side nearwall cooling channels.

Cooling fluids may also be passed to the trailing edge cooling channelvia one or more trailing edge supply channels The cooling fluids may bemetered through metering holes into the trailing edge cooling channel.The cooling fluids may flow into the zigzag cooling flow channels wherethe pin fins direct the cooling fluids in a nonlinear motion to thetrailing edge, where the cooling fluids are exhausted. The coolingfluids in the trailing edge cooling channel receive heat from the outerwall forming the pressure and suction sides and from the pin fins.

An advantage of the internal cooling system is that the corrugatedinsert creates periodic impingement and sufficient cooling fluid mixingto cool the airfoil

These and other embodiments are described in more detail below

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part ofthe specification, illustrate embodiments of the presently disclosedinvention and, together with the description, disclose the principles ofthe invention

FIG. 1 is a perspective view of a turbine vane with aspects of thisinvention

FIG. 2 is a cross-sectional view of the turbine vane taken at sectionline 2-2 in FIG. 1.

FIG. 3 is a detailed view of the pressure side nearwall cooling channel.

FIG. 4 is a detailed view of the trailing edge cooling channel of thecooling system shown in FIG. 2.

FIG. 5 is a detailed view of the midchord cooling channel of the coolingsystem shown in FIG. 2

FIG. 6 is a side view of a three dimensional model of the cooling systemwithin the turbine vane in FIG. 1.

FIG. 7 is a perspective view of the three dimensional model of thecooling system shown in FIG. 6.

FIG. 8 is schematic, cross-sectional diagram of a portion of the coolingsystem of FIG. 2.

FIG. 9 is a detail view of a portion of the cooling system taken at thedetail line in FIG. 8.

FIG. 10 is a perspective view of a portion of the cooling system of FIG.2.

FIG. 11 is a detail view of a portion of the cooling system taken atdetail line 11-11 in FIG. 10.

FIG. 12 is a cross-sectional view of an alternative embodiment of theturbine vane taken at section line 2-2 in FIG. 1

FIG. 13 is a detailed view of an alternative embodiment of the pressureside nearwall cooling channel.

FIG. 14 is a detailed view of an alternative embodiment of the trailingedge cooling channel of the cooling system shown in FIG. 2.

FIG. 15 is a detailed view of an alternative embodiment of the midchordcooling channel of the cooling system shown in FIG. 2.

FIG. 16 is a perspective view of a turbine blade with aspects of thisinvention.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIGS. 1-16, an airfoil 10 for a gas turbine engine in whichthe airfoil 10 includes an internal cooling system 14 formed from one ormore midchord cooling channels 16 with a corrugated insert 18 positionedtherein and creating nearwall leading edge, pressure side and suctionside nearwall cooling channels 20, 22, 24 is disclosed The corrugatedinsert 18 may be formed from a wall 26 that oscillates in a repeatingpattern between peaks 28 and valleys 30, such that the peaks 28 arecloser to an inner surface 50 of an outer wall 32 forming a generallyelongated hollow airfoil 34 of the airfoil 10 The corrugated insert 18may work in concert with the rows 36 of partition walls 38 to createperiodic impingement on the inner surface 50 of the outer wall 32,specifically the surfaces 40 leading from the valleys 30 to the peaks 28moving toward a trailing edge 42 of the generally elongated hollowairfoil 34 direct the fluids toward the outer wall 32 Such coolingsystem 14 may provide adequate cooling for use in environments in whichfew, if any, cooling holes are desired, such as in crude oil engineapplications.

In at least one embodiment, the turbine airfoil 10 may be formed from agenerally elongated hollow airfoil 34 formed from an outer wall 32, andhaving a leading edge 44, a trailing edge 42, a pressure side 46, asuction side 48, and the internal cooling system 14 positioned withininterior aspects of the generally elongated hollow airfoil 34 In oneembodiment, the turbine airfoil 10 may be a stationary vane, as shown inFIG. 1, such as a turbine vane, with inner and outer endwalls. Inanother embodiment, the turbine airfoil 10 may be a rotary blade, asshown in FIG. 16, such as a turbine blade As shown in FIGS. 2, 6, 7 and12, the turbine airfoil 10 may include one or more midchord coolingchannels 16 with one or more corrugated inserts 18 positioned thereinand creating a leading edge nearwall cooling channel 20 between theleading edge 44 and the corrugated insert 18, a suction side nearwallcooling channel 24 between the suction side 48 and the corrugated insert18 and a pressure side nearwall cooling channel 22 between the pressureside 46 and the corrugated insert 18. The corrugated insert 18 may beformed from a wall 26 that oscillates in a repeating pattern betweenpeaks 28 and valleys 30, such that the peaks 28 are closer to an innersurface 50 of the outer wall 32 forming the generally elongated hollowairfoil 34. In at feast one embodiment, the peaks 28 and valleys 30 maybe generally curved. Portions of the corrugated insert 18 extendingbetween the peaks 28 and valleys 30 may be generally linear.

The turbine airfoil 10 may also include a plurality of rows 36 ofpartition walls 38 extending from the inner surface 50 forming the outerwall 32 and into the midchord cooling channel 16 On or more partitionwalls 38 may include gaps 52 therein. The gaps 52 maybe shorter inlength than the individual sections of the partition walls 38. The rows36 of partition walls 38 may be generally aligned with a direction 54 ofcooling fluid flow from the leading edge 44 chordwise toward thetrailing edge 42. In at least one embodiment, the partition walls 38 maybe orthogonal with the leading edge 44 In at least one embodiment, thepartition walls 38 may be orthogonal with the leading edge 44 or thetrailing edge 42, or both At least a portion of the peaks 28 in thecorrugated insert 18 extending radially outward may be aligned with thegaps 52 within at least a portion of at least one partition wall 38 Suchalignment of the gaps 52 with the peaks 28 creates periodic impingementupon the impingement surfaces 40 and partial lateral, spanwise movementand mixing of the cooling fluids In particular, the corrugated insert 18functions in concert with the rows 36 of partition walls 38 to createperiodic impingement on the corrugated insert 18, specifically on thosesurfaces 40 leading from the valleys 30 to the peaks 28 moving towardthe trailing edge 42.

As shown in FIGS. 2, 5 and 9-11, the plurality of rows 36 of partitionwalls 38 may extend from the inner surface 50 into the pressure sidenearwall cooling channel 22 Similarly, the plurality of rows 36 ofpartition walls 38 may extend from the inner surface 50 into the suctionside nearwall cooling channel 24 The rows of partition walls 38 mayextend in a direction from the leading edge 44 chordwise toward thetrailing edge 42. As shown in FIGS. 2 and 12, the leading edge nearwallcooling channel 20 may not include partition walls 38 or othercomponents. In another embodiment, the leading edge nearwall coolingchannel 20 may include partition walls 38 or other impingementcomponents One or more inlets 56 may be positioned in the corrugatedinsert 18 at the leading edge nearwall cooling channel 20 to passcooling fluid from interior aspects of the corrugated insert 18 to theleading edge nearwall cooling channel 20 The inlets 56 may function asan impingement holes as the compressed air flows from inner aspects ofthe corrugated insert 18 through the inlets 56 and impinges on abackside, inner surface of the outer wall 32 forming the leading edge 44

In at least one embodiment, as shown in FIGS. 5-10 and 15, the partitionwall gaps 52 may extend for a partial length or an entire length of thepartition wall 38. One or more of the partition walls 38 may be linear.In at least one embodiment, each of the partition walls 38 may be linearand each of the partition walls 38 may be parallel with each other. Thepartition walls 38 may have a cross-sectional area with one or more ofthe following shapes: square, rectangular and trapezoidal, or otherappropriate shape.

In another embodiment, as shown in FIG. 15, one or more partition walls38 may be formed from first and second subpartition walls 58, 60. Thesecond subpartition wall 60 may be offset laterally from firstsubpartition wall 58, and the first and second subpartition walls 58, 60may be staggered in an alternating manner moving in a direction from theleading edge 44 toward the trailing edge 42. In another embodiment, eachpartition wall 38 may be formed from the first and second subpartitionwalls 58, 60 with the same configuration set forth immediately aboveAdjacent partition walls 38 may be spaced from each other equidistant,randomly, in a pattern or in another manner. In at least one embodiment,a second subpartition wall 60 may be positioned along an axis 62 that isequidistant from the first subpartition wall 58 within a same partitionwall 64 as the second subpartition wall 60 and a first subpartition wall58 within an adjacent partition wall 66.

The cooling system 14 may also include one or more miniribs 68, as shownin FIGS. 3, 5, 9-11, 13 and 15, extending from the inner surface 50forming the outer wall 32 and extending between adjacent partition walls38. The miniribs 68 may be nonparallel with the partition walls 38 andmay be shorter in height extending from the inner surface 50 thanadjacent partition ribs 38 The miniribs 68 may have a cross-sectionalarea with one or more of the following shapes: square, rectangular, andtrapezoidal, or other appropriate shape. A cross-sectional area of aminirib 68 may be less than a cross-sectional area of the partition wall38. In at least one embodiment, the cross-sectional area of a minirib 68may be less than one quarter of the cross-sectional area of thepartition wall 38. In yet another embodiment, the cross-sectional areaof a minirib 68 may be less than one eight of the cross-sectional areaof the partition wall 38 The plurality of miniribs 68 may be alignedwith each other and may be orthogonal to the adjacent partition walls 38The miniribs 68 may extend from a partition wall 38 to an adjacentpartition wall 38. In another embodiment, neither end of the miniribs 68contacts the partition walls 38, as shown in FIGS. 5 and 15 In at leastone embodiment, a plurality of miniribs 68 may extend between eachadjacent partition walls 38 between gaps 52 In at least one embodiment,at least four miniribs 68 extend between adjacent partition walls 38between gaps 52. In addition, there may exist one or more miniribs 68positioned within a gap 52 between two portions of a partition wall 38within a single partition wall 38

The cooling system 14 may also include one or more trailing edge coolingchannels 70, as shown in FIGS. 4 and 14, positioned between the midchordcooling channel 16 and the trailing edge 42 of the generally elongatedhollow airfoil 34. The trailing edge cooling channel 70 may include aplurality of pin fins 72 extending from the outer wall 32 forming thepressure side 46 to the suction side 48 and forming zigzag cooling flowchannels 74 within the trailing edge cooling channel 70 At least aportion of the pin fins 72 may have cross-sectional areas with a leadingedge 76 and a trailing edge 78 that is positioned on a downstream corner80 and separated from the leading edge 76 by a concave side surface 82and a convex side surface 84 on an opposite side of the pin fin 72 fromthe concave side 82. One or more of the zigzag cooling flow channels 74may be formed from a plurality of pin fins 72 aligned such that theconcave and convex side surfaces 82, 84 alternate moving towards thetrailing edge 42 As shown in FIGS. 4 and 14, a first upstream pin fin 86may have a cross-sectional area formed from an upstream section 88 and adownstream section 90. The upstream section 88 may be generally linearwith a constant width, and the downstream section 90 may be generallylinear with a tapered width that reduces in width moving towards thetrailing edge 42 The upstream and downstream sections 88, 90 may benonlinear and nonorthogonal with each other.

During use, cooling fluids may be supplied from a compressor or othersuch source to the inner aspect of the corrugated insert 18 of theinternal cooling system 14. Cooling fluids are passed through the inlets56 into the leading edge nearwall cooling channel 20 where the fluidsseparate with a portion flowing into the pressure side nearwall coolingchannel 22 and a portion flowing into the suction side nearwall coolingchannel 24. The peaks 28 and valleys 30 of the corrugated insert 18create periodic impingement on the inner surface 50 of the outer wall32. The partition walls 38 also direct the cooling fluids towards thetrailing edge 42, and in at least some embodiments, create a nonlinearflow path toward the trailing edge to increase convection of heat fromthe outer wall to the cooling fluid. The cooling fluid may be exhaustedthrough film cooling holes 92 at downstream ends of the pressure andsuction side nearwall cooling channels 22, 24.

Cooling fluids may also be passed to the trailing edge cooling channel70 via one or more trailing edge supply channels 94. The cooling fluidsmay be metered through metering holes 96 into the trailing edge coolingchannel 70. The cooling fluids may flow into the zigzag cooling flowchannels 74 where the pin fins 72 direct the cooling fluids in anonlinear, back and forth motion to the trailing edge 42, where thecooling fluids are exhausted. The cooling fluids in the trailing edgecooling channel 70 receive heat from the outer wall 32 forming thepressure and suction sides 46, 48 and from the pin fins 72

The foregoing is provided for purposes of illustrating, explaining, anddescribing embodiments of this invention. Modifications and adaptationsto these embodiments will be apparent to those skilled in the art andmay be made without departing from the scope or spirit of thisinvention.

We claim:
 1. A turbine airfoil, comprising: a generally elongated hollowairfoil formed from an outer wall, and having a leading edge, a trailingedge, a pressure side, a suction side, and a cooling system positionedwithin interior aspects of the generally elongated hollow airfoil; atleast one midchord cooling channel with at least one corrugated insertpositioned therein and creating a leading edge nearwall cooling channelbetween the leading edge and the corrugated insert, a suction sidenearwall cooling channel between the suction side and the corrugatedinsert and a pressure side nearwall cooling channel between the pressureside and the corrugated insert; wherein the corrugated insert is formedfrom a wall that oscillates in a repeating pattern between peaks andvalleys, such that the peaks are closer to an inner surface of the outerwall forming the generally elongated hollow airfoil; a plurality of rowsof partition walls extending from the inner surface forming the outerwall and into the midchord cooling channel, wherein the partition wallsinclude gaps therein and wherein the rows of partition walls aregenerally aligned with a direction of cooling fluid flow from theleading edge chordwise toward the trailing edge; and wherein at least aportion of the peaks in the corrugated insert extending radially outwardare aligned with the gaps within at least a portion of at least onepartition wall
 2. The turbine airfoil of claim 1, wherein at least onepartition wall includes gaps therein that extend an entire length of theat least one partition wall
 3. The turbine airfoil of claim 1, whereinat least one partition wall is linear.
 4. The turbine airfoil of claim1, wherein each of the partition walls is linear and each of thepartition walls are parallel with each other.
 5. The turbine airfoil ofclaim 1, wherein at least one partition wall is formed from a first andsecond subpartition walls, wherein the second subpartition wall isoffset laterally from first subpartition wall and wherein the first andsecond subpartition walls are staggered in an alternating manner movingin a direction from the leading edge toward the trailing edge.
 6. Theturbine airfoil of claim 1, wherein each partition wall is formed from afirst and second subpartition walls, wherein the second subpartitionwall is offset laterally from first subpartition wall and wherein thefirst and second subpartition walls are staggered in an alternatingmanner moving in a direction from the leading edge toward the trailingedge.
 7. The turbine airfoil of claim 6, wherein a second subpartitionwall is positioned along an axis that is equidistant from a firstsubpartition wall within a same partition wall as the secondsubpartition wall and a first subpartition wall within an adjacentpartition wall.
 8. The turbine airfoil of claim 1, further comprising aplurality of miniribs extend from the inner surface forming the outerwall and extending between adjacent partition walls, wherein theminiribs are nonparallel with the partition walls and are shorter inheight extending from the inner surface than adjacent partition walls 9.The turbine airfoil of claim 8, wherein the plurality of miniribs arealigned with each other and are orthogonal to the adjacent partitionwalls
 10. The turbine airfoil of claim 1, further comprising at leastone trailing edge cooling channel positioned between the at least onemidchord cooling channel and the trailing edge of the generallyelongated hollow airfoil, wherein the at least one trailing edge coolingchannel includes a plurality of pin fins extending from the outer wallforming the pressure side to the suction side and forming zigzag coolingflow channels within the at least one trailing edge cooling channel 11.The turbine airfoil of claim 10, wherein at least a portion of the pinfins have cross-sectional areas with a leading edge, a trailing edgethat is positioned on a downstream corner and separated from the leadingedge by a concave side surface and a convex side surface
 12. The turbineairfoil of claim 11, wherein at least one of the zigzag cooling flowchannels is formed from a plurality of pin fins aligned such that theconcave and convex side surfaces alternate moving towards the trailingedge.
 13. The turbine airfoil of claim 11, wherein a first upstream pinfin has a cross-sectional area formed from an upstream section and adownstream section, wherein the upstream section is generally linearwith a constant width, and the downstream section is generally linearwith a tapered width that reduces in width moving towards the trailingedge, wherein the upstream and downstream sections are nonlinear andnonorthogonal with each other
 14. A turbine airfoil, comprising: agenerally elongated hollow airfoil formed from an outer wall, and havinga leading edge, a trailing edge, a pressure side, a suction side, and acooling system positioned within interior aspects of the generallyelongated hollow airfoil; at least one midchord cooling channel with atleast one corrugated insert positioned therein and creating a leadingedge nearwall cooling channel between the leading edge and thecorrugated insert, a suction side nearwall cooling channel between thesuction side and the corrugated insert and a pressure side nearwallcooling channel between the pressure side and the corrugated insert;wherein the corrugated insert is formed from a wall that oscillates in arepeating pattern between peaks and valleys, such that the peaks arecloser to an inner surface of the outer wall forming the generallyelongated hollow airfoil; a plurality of rows of partition wallsextending from the inner surface forming the outer wall and into themidchord cooling channel, wherein the partition walls include gapstherein and wherein the rows of partition walls are generally alignedwith a direction of cooling fluid flow from the leading edge chordwisetoward the trailing edge; wherein at least a portion of the peaks in thecorrugated insert extending radially outward are aligned with the gapswithin at least a portion of at least one partition wall; a plurality ofminiribs extending from the inner surface forming the outer wall andextending between adjacent partition walls, wherein the miniribs arenonparallel with the partition walls and are shorter in height extendingfrom the inner surface than adjacent partition walls; at least onetrailing edge cooling channel positioned between the at least onemidchord cooling channel and the trailing edge of the generallyelongated hollow airfoil, wherein the at least one trailing edge coolingchannel includes a plurality of pin fins extending from the outer wallforming the pressure side to the suction side and forming zigzag coolingflow channels within the at least one trailing edge cooling channel; andwherein at least a portion of the pin fins have cross-sectional areaswith a leading edge, a trailing edge that is positioned on a downstreamcorner and separated from the leading edge by a concave side surface anda convex side surface
 15. The turbine airfoil of claim 14, wherein eachof the partition walls is linear and each of the partition walls isparallel with each other.
 16. The turbine airfoil of claim 14, whereineach partition wall is formed from a first and second subpartitionwalls, wherein the second subpartition wall is offset laterally fromfirst subpartition wall and wherein the first and second subpartitionwalls are staggered in an alternating manner moving in a direction fromthe leading edge toward the trailing edge.
 17. The turbine airfoil ofclaim 16, wherein a second subpartition wall is positioned along an axisthat is equidistant from a first subpartition wall within a samepartition wall as the second subpartition wall and a first subpartitionwall within an adjacent partition wall
 18. The turbine airfoil of claim14, wherein the miniribs are aligned with each other and are orthogonalto the adjacent partition walls.
 19. The turbine airfoil of claim 14,wherein a first upstream pin fin has a cross-sectional area formed froman upstream section and a downstream section, wherein the upstreamsection is generally linear with a constant width, and the downstreamsection is generally linear with a tapered width that reduces in widthmoving towards the trailing edge, wherein the upstream and downstreamsections are nonlinear and nonorthogonal with each other and wherein atleast one of the zigzag cooling flow channels is formed from a pluralityof pin fins aligned such that the concave and convex side surfacesalternate moving towards the trailing edge.
 20. A turbine airfoil,comprising: a generally elongated hollow airfoil formed from an outerwall, and having a leading edge, a trailing edge, a pressure side, asuction side, and a cooling system positioned within interior aspects ofthe generally elongated hollow airfoil; at least one midchord coolingchannel with at least one corrugated insert positioned therein andcreating a leading edge nearwall cooling channel between the leadingedge and the corrugated insert, a suction side nearwall cooling channelbetween the suction side and the corrugated insert and a pressure sidenearwall cooling channel between the pressure side and the corrugatedinsert; wherein the corrugated insert is formed from a wall thatoscillates in a repeating pattern between peaks and valleys, such thatthe peaks are closer to an inner surface of the outer wall forming thegenerally elongated hollow airfoil; a plurality of rows of partitionwalls extending from the inner surface forming the outer wall and intothe midchord cooling channel, wherein the partition walls include gapstherein and wherein the rows of partition walls are generally alignedwith a direction of cooling fluid flow from the leading edge chordwisetoward the trailing edge; wherein at least a portion of the peaks in thecorrugated insert extending radially outward are aligned with the gapswithin at least a portion of at least one partition wall; wherein eachpartition wall is formed from a first and second subpartition walls,wherein the second subpartition wall is offset laterally from firstsubpartition wall and wherein the first and second subpartition wallsare staggered in an alternating manner moving in a direction from theleading edge toward the trailing edge; a plurality of miniribs extendingfrom the inner surface forming the outer wall and extending betweenadjacent partition walls, wherein the miniribs are nonparallel with thepartition walls and are shorter in height extending from the innersurface than adjacent partition walls; at least one trailing edgecooling channel positioned between the at least one midchord coolingchannel and the trailing edge of the generally elongated hollow airfoil,wherein the at least one trailing edge cooling channel includes aplurality of pin fins extending from the outer wall forming the pressureside to the suction side and forming zigzag cooling flow channels withinthe at least one trailing edge cooling channel; wherein at least aportion of the pin fins have cross-sectional areas with a leading edge,a trailing edge that is positioned on a downstream corner and separatedfrom the leading edge by a concave side surface and a convex sidesurface; and wherein the upstream and downstream sections are nonlinearand nonorthogonal with each other and wherein at least one of the zigzagcooling flow channels is formed from a plurality of pin fins alignedsuch that the concave and convex side surfaces alternate moving towardsthe trailing edge.